Till now I have learned that light has fastest speed. But I have also noticed that wherever it travels it only experiences retardation. So I wanted to know if light ever felt acceleration naturally in ...

Two bodies cannot attract each other as a body contains mass and mass is a constituent of atoms and molecules,held by electrical force.The electrical force is too weak to attract other objects.
And ...

I took the way of classification of Lorentz group representations from Sexl, Urbantke, Relativity, groups and particles (Germ. ed. 1975). But I don't understand it as I outline in the following:
In ...

Suppose we can travel on a spacecraft near the speed of light, how long it would take for the person on the spacecraft to travel one light year, not to a person observing him/her from Earth, if there ...

Before you say I'm wrong consider this, Einstein is supposedly the first person to get completely get rid of the various aether models that were proposed. But didn't Einstein actually prove them right ...

I know that besides the effects of Newton's theory of Gravitation on the satellite's motion, one has to take account of the retardation of the satellite's clocks when compared to earth-fixed clocks. ...

A pendulum clock ticks slower on top of a mountain and ticks faster at ground level, but an atomic clock ticks faster on top of a mountain and ticks slower at ground level.
Gravity affects pendulum ...

In the video on YouTube, The Real Meaning of E=mc² | PBS| Space Time Studios, it claims that a ticking watch has more mass then a non ticking watch due to the intrinsic KE, PE and thermal energy of ...

I had received a homework problem by my professor. Please consider part (b) of the problem.
Can part (b) be solved only using special relativity? And how can you solve this? I think that Alice will ...

I have heard that a positron is like an electron moving backward through time. Can someone elucidate this statement for me. I would like to hear a deeper explanation of what we believe anti-matter to ...

BACKSTORY
I read today newspaper and made discovery of planet Cygnus (in news paper of course :v) that human can live there! The distance is 1400 Lightyear. Assuming I travel with the world fastest ...

Suppose light is travelling in a straight line parallel to $y$-axis takes time $t$ to reach from $y_1$ to $y_2$ in a reference frame $S$. Let there be another frame, $S'$, which is travelling parallel ...

Say Alice is on on one end of a train moving at c/2 and there is a mirror at the other end. If she turns on a flashlight aimed at the mirror, from her perspective it takes the same time for the light ...

I am trying to prove the Lorentz invariance of the (left-handed) Weyl Lagrangian:
$$\mathcal L=i\psi^\dagger\bar\sigma^\mu\partial_\mu\psi$$
A Lorentz transformation is realized as
$\psi\to M\psi$, ...

Am I correct in thinking that if two spacetime events are coincident in one frame of reference, then they are coincident in all frames of reference, i.e. coincidence of spacetime events is a Lorentz ...

Inertia is directly proportional to mass but what happens when something travel to speed near to light. Its relativistic mass tends to infinity but that is false mass so I want to know if inertia is ...

My apologies if my question is really idiotic, but I ask sincerely because I want to learn. Based on this question and lots of other places on the web, this topic seems to be really confusing.
Let's ...

Given that the Minkowski metric does not change under a Lorentz transformation, the scale factor does not change in the special case when it is equal to 1.
Is this result true in general? i.e. is the ...

We have a star of constant luminosity $L$. We want to prove that the components $T_{00}$, $T_{10}$, $T_{01}$ and $T_{11}$ are all the same for the event $(ct,x,0,0)$ and they are all $L/(4\pi x^2)$.
...

I just learned that, according to Einstein's relativity theory, time reaches zero for an observer (light) when traveling at the speed of light, so everything is supposed to be at the same place in the ...

Please pardon my beginners understanding.
I was thinking about the wave function of a "free particle",
$\psi(x,t)$, where $\psi(x,0)$ is the initial condition. Writing $\psi (x,t)$ as $\sum\limits_n ...